Waveguides are devices that transmit optical signals from one location to another within an integrated circuit. Waveguides have been implemented in electronic-photonic integrated circuits to decrease circuit size and increase circuit performance. Present methods for manufacturing waveguides involve etching a slot within a silicon wafer. Etching the silicon substrate, however, is difficult to control. Due to present etching methods, the waveguide slot may vary in depth along the length of the waveguide. Moreover, etching may also create non-uniform sidewalls. These waveguide defects or geometric irregularities may cause dispersion of the optical mode. As a result of the present inaccurate waveguide manufacturing methods, waveguide performance and/or efficiency may be adversely affected.